Centrifugal type ore pulverizer with explosion prevention means



June 5, 1956 M, ROMERA 2,749,052

CENTRIFUGAL TYPE; ORE PULVEIRIZER WITH EXPLOSION PREVENTION MEANS Filed May 11, 1953 2 Sheets-Sheet 1 O .1. 5 INVENTOR.

MANUEL. ROMERA ATTORNEYS June 5, 1956 M. ROMERA CENTRIFUGAL. TYPE ORE PULVERIZER WITH EXPLOSION PREVENTION MEANS 2 Sheets-Sheet 2 Filed May 11, 1953 INVENTOR.

MANUEL. ROMERA ATTORN vs United States Patent CENTRIFUGAL TYPE ORE PULVERIZER WITH EXPLOSION PREVENTION MEAN Manuel Romera, San Francisco, Calif.

Application May 11, 1953, Serial No. 353,973

Claims. (Cl. 241-31) The present invention relates to improvements in an ore pulverizer. It consists of the combinations, constructions, and arrangement of parts, as hereinafter described and claimed.

Among the various objects of this invention, it is proposed to provide a pulverizer, which is adapted for reducing various types of ores and recovering elements therefrom, such as sulphur, magnesium and copper; the reduction and recovery of the elements from the ores being accomplished rapidly and at a relatively low cost; and the entire operation being carried out with the utmost safety.

In the mining of sulphur, for example, steam is employed for melting this element, requiring expensive equipment. Moreover, when sulphur-containing ore is fed through the conventional type of hammer mill, the sulphurous gases must be withdrawn from the mill by elaborate suction apparatus in order to prevent explosions from occurring in the mill. It is a common practice to burn these gases after they have been conveyed away from the mill. Of course, all of this additional equipment increases the cost of production, which is prohibitive when operating with low grade ore.

Generally speaking, I provide a unitary structure wherein the entire operation of recovering sulphur, or other element, may be accomplished without requiring extraneous steam and suction equipment to be employed.

Moreover specifically stated, it is proposed to provide a pulverizer of the centrifugal type, whereby the incoming ore may be pulverized so as to liberate the desired element, for example sulphur, and to separate the undesired rock therefrom, all in a continuous operation, and without any danger of explosion.

It is proposed to form the ore into a descending curtain, and to subject the ore to repeated beating actions as the curtain descends, crushing ore against ore until the rock content has been reduced to such an extent as to free the greater portion of the desired element therefrom. Provision is made for delivering a non-combustible gas to the interior of the ore pulverizer so as to displace the air therefrom, or to dilute the oxygen to such an extent as to prevent sulphurous gases, for instance, from exploding.

Another object is to provide an ore reducer having inner and outer drums mounted one within the other to define a passageway therebetween, through which an annular curtain of descending ore may be fed. While passing downwardly, the ore particles disposed along the surfaces of this curtain are struck by beater blades se cured to these drums so as to project into the passageway. The ore is retained in the reducer and subjected to beating actions until it has been crushed to the proper state, whereupon the finer particles are separated from the coarser tailings.

Other objects and advantages will appear as the specification continues. The novel features will be set forth in the claims hereunto appended.

Drawings For a better understanding of this invention, reference should be had to the accompanying drawings, forming part of this application, in which:

Figure l is a vertical sectional view taken through my ore pulverizer, parts being shown in elevation;

Figure 2 is a horizontal sectional view taken along the line 11-11 of Figure 1;

Figures 3 and 4 are fragmentary perspective views of the outer and inner drums, respectively, when looking in the direction of the arrows III and IV of Figure 2; and

Figure 5 is an enlargedview of a portion of Figure 2, disclosing ore being crushed by beater plates carried by the inner and outer drums.

While I have shown only the preferred form of my invention, it should be understood that various changes, or modifications, may be made within the scope of the annexed claims without departing from the spirit thereof.

Detailed description Referring to the drawings, it will be noted that inner and outer drums A and B, respectively, are mounted concentrically one within the other for rotation about the axis of an upright shaft C. These drums have annular walls 10 and 11, respectively, which are arranged in confronting and spaced-apart relation to define a passageway D therebetween through which ore E may be fed in a descending curtain for reduction.

As clearly shown in Figures 1 and 2, the inner drum A is adapted to be rotated in the direction of the arrow 12 by a suitable drive F. The outer drum B may be turned in the opposite direction, as indicated by the arrow 14, by a variable-speed drive G. These structural details will be set forth as the specification continues.

For the purpose of supporting the outer drum B, a stand H has been provided with a bearing 15 therein to receive a hub 16 projecting downwardly from the bottom 17 of this drum (see Figure 1). Moreover, standards 18 extend upwardly from a base 19, and are provided at their tops with a suitable bearing 2%, which surrounds a sleeve 21 rising from a cover 22 of the outer drum. Both of these hearings are arranged concentrically relative to the shaft C.

In its details, the drive G has been shown as including a bevel gear 23 secured to the bottom 17, which may be driven by a pinion 24 fixed to a stub shaft 25. For rotating this shaft at variable speeds, it has been provided with a multiple-stepped pulley 26 driven by a belt 27. Of course, any other means may be resorted to for rctating the outer drum B at the desired speed. The drive F includes a bevel gear 23' secured to the upright shaft C, and a pinion 24 driven by a shaft 25'. In actual practice, the inner drum is turned at a relatively high speed, while the outer drum is rotated at a slow speed.

In Figure 1, the upright shaft C has been illustrated as having its lower end journalled in a thrust bearing 28, while its upper end is supported in a conventional bearing 29 secured in a bracket 30 mounted on one of the standards 18. The inner drum A is cup-shaped, and is secured to the shaft C so as to rotate therewith. Any suitable means may be employed for fixing the drum A to the shaft C, for example, the latter may have a clamping nut 31 threaded thereon for anchoring the bottom 32 of the inner drum to the shaft. Of course, this bottom could be welded to the shaft C, if desired.

It will be noted that a conical-shaped bowl J is fastened to the upright shaft C by a clamping nut 33, or other suitable means, so as to turn therewith. This bowl has a wall 34 that slopes upwardly and outwardly to define a marginal rim 35 at its top. T his rim registers with the upper end of the drum and constitutes a support for the latter. For delivering the incoming ore E to the bowl, I have shown a chute 36, which is arranged to feed the ore through the sleeve 21 so as to gravitate into the bowl.

Upon rotating the shaft. C andthe bowl I at a sufficient- 1y high speed, ore will be discharged from the bowl by centrifugal force, as indicated by the arrows 37, with the ore gravitating into the upper end of the annular passageway D. Impact bars 38 may be secured to the underncath side of the cover 22 to prevent the latter from wearing away as the ore is discharged from the bowl. Inclined feeder blades 39 (see Figures 1 and 4) may be attached to the outer surface of the inner drum, near its top, for the purpose of urging the ore downwardly in the passageway D during operation of the pulverizer.

As the ore gravitates through the passageway D, it is formed into an annular descending curtain, as suggested in Figure 1. Heater blades 40 and 41 are secured to the upright walls 10 and 11, respectively, in inclined relation therewith, so as to project into the passageway D. The blades 40 on one drum are positioned and coact with the blades 41 on the other drum so as to crush ore caught thcrcbetwcen (see Figure it being noted that the drums are rotated in opposite directions. The blades 40 and 41 beat the ore on the inner and outer surfaces, respectively, of the descending curtain, with impact blows extending in directions to impel the ore into the interior portion of the curtain defined between these surfaces, to thereby crush ore against ore.

Moreover, the drums A and B have a plurality of spaced-apart ribs 42 and 43, respectively, secured to their upright walls. These ribs are disposed horizontally and extend circumferentially around the confronting walls and 11, respectively, thereby projecting into the passageway D so as to retard descending of the ore therethrough. The ribs 42 are staggered relative to the ribs 43 (see Figure l). The beater blades are located between adjacent blades 42 on the exterior surface of the inner drum A (see Figure 4), while the beater blades 41 are disposed between adjacent ribs 43 on the interior surface of the outer drum B (see Figure 3).

It will be apparent from Figure I that the ribs 42 gradually increase in width from the top to the bottom of the inner drum, thus causing the thickness of the curtain of descending ore in the passageway D to diminish as the curtain descends. In other words, the particles of ore must be reduced in size in order to pass consecutive ribs.

When this reduced ore finally drops into the bottom of the outer drum B, it is thrown by centrifugal force through outlet openings 44, which are formed in the upright wall 11 near the bottom thereof. At this time, a classifier K will separate the finer particles 45 of the desired element, such as sulphur, from the coarser parts 46 of ore, for instance, the tailings of granite rock.

With respect to the structural details of the classifier K, there has been provided an inverted truncated conical-shaped screen 47, which surrounds the exterior of the outer drum B, with its smaller end disposed below and adjacent to the outlet openings 44. This screen flares upwardly and outwardly relative to the outer drum so that the coarser particles or tailings 46 will move upwardly thereover for discharge through a housing 48. The finer particles 45, or desired element liberated from the ore, will pass through the screen for delivering into an outlet conduit 49, from which they may be recovered.

As previously stated, various types of ores may be reduced in my pulverizer. For example, when sulphur is to be extracted from granite or other rock, this type of ore is fed into the chute 36. In this event, the powdered sulphur will constitute the finer particles 45, while the coarser particles 46 will be made up of the granite or other rock residue.

There is always an inherent danger of explosions occurring in pulverizing sulphur ore. For this reason, I

4 convey a non-combustible gas, such as cooled and filtered exhaust gases from an engine, to the interior of the drums A and B, under sufiicient pressure to displace air therefrom, or at least dilute the oxygen to a point that will preclude an explosion.

These gases may be delivered by a conduit 50 to an axial bore 51 provided in the upright shaft C. This shaft, in turn, has a series of radial passages 52 therein for delivering the incoming gases to the hopper J and the inner drum A. The upright wall 10 of the latter is provided with apertures 53 through which these gases will flow to the annular passageway D, wherein the reduction of ore is accomplished. The non-combustible gases not only prevent the sulphur from exploding, but further preclude vacuum from forming in back of the beater blades 40 as the inner drum is rotated.

Summary Having thus described the various structural features of my ore pulverizing, the operation thereof is summarized briefly as follows:

Initially, the drives F and G are set in motion so as to rotate the inner and outer drums A and B, respectively, in opposite directions and at the proper speed. Now ore E is fed to the chute 36 for delivering through the sleeve 21 to the bowl J, the latter being rotated with the inner drum. As the ore drops into this bowl, it is thrown outwardly by centrifugal force, striking the impact bars 38 and then gravitating into the passageway D provided between the drums.

As the ore gravitates down, it is formed into an annular descending curtain, the thickness of which gradually diminishes as the curtain descends, due to the progressively increasing widths of the ribs 42 from the top to the bottom of the inner drum. The heater blades 40 and 41 strike the ore disposed along the inner and outer surfaces, respectively, of the curtain, crushing ore against ore. The reduced ore drops into the bottom portion of the outer drum B, and is thrown by centrifugal force through outlet openings 44 into the classifier K. Here the fine particles of the ore are separated from the coarser ma terial. All of these operations are carried out in the presence of a non-combustible gas delivered through the conduit 50 to the interior of the ore reducer, thereby preventing any explosion therein.

I claim:

1. In an ore pulverizer: inner and outer drums mounted concentrically one within the other for rotation; these drums having upright annular walls spaced from each other, and arranged in confronting rclation; these walls defining a passageway therebetween through which ore may descend; each drum having a plurality of spacedapart horizontally-disposed annular ribs on its wall; these ribs projecting into the passageway to retard descending of the ore therethrough; a series of inclined beater blades secured to each upright wall and located between adjacent ribs; the blades on one drum being positioned and coacting with those on the other drum to crush ore caught therebetween during rotation of the drums; and means for turning the drums at different speeds relative to one another.

2. In an ore crusher: a cup-shaped drum defining an upright annular wall and a bottom; means mounting this drum for rotation; the upright wall having outlet opcn ings, near the bottom of the drum, through which or: contained in the drum may be thrown by centrifugal force when the drum is turned; an inverted truncated conical-shaped screen surrounding the exterior of the drum, with its smaller end disposed below and adjacent to the outlet openings of the drum; this screen flaring upwardly and outwardly relative to the drum so that larger particles of ore thrown outwardly through the drum openings will move upwardly thercover for discharge, while finer particles of ore will pass through the screen; and means for rotating the drum at a sutficient speed to throw the larger ore particles upwardly over the top of the screen.

3. In an ore pulverizer: inner and outer drums mounted concentrically one Within the other for rotation about a vertical axis; said drums having upright annular walls spaced from each other and arranged in confronting relation; these walls defining a cylindrical passageway therebetween through which ore may descend in the form of a curtatin; a conical-shaped bowl adapted to receive material to be pulverized and carried by the upper end of the inner drum so as to be rotatable therewith; means for guiding the material leaving the bowl and directing it into the cylindrical passageway so that the material will form a descending curtain; each drum having a plurality of spaced-apart, horizontally-disposed annular ribs on its wall; these ribs projecting into the passageway; a series of inclined blades secured to each wall and located between adjacent ribs; the blades on the inner drum being positioned to strike ore flowing downwardly with the curtain and to crush this ore against the blades on the outer drum or on any ore that at the moment covers the blades; and means for rotating the drums at difierent speeds and in opposite directions to one another.

4. In an ore pulverizer: inner and outer drums mounted one within the other for rotation about a vertical axis; these drums having confronting walls spaced from each other and defining a passageway therebetween through which ore may be fed in a descending curtain; blades secured to each of these walls and being inclined to project into the passageway; the inner drum having a means for feeding the gas to the inner drum including means for feeding some of the gas to the interior of the bowl for precluding any explosion therein.

References Cited in the file of this patent UNITED STATES PATENTS Re. 1,919 Gowdy Mar. 28, 1865 227,064 Sewell Apr. 27, 1880 271,138 Sharpneck Ian. 23, 1883 500,916 Leonhardt July 4, 1893 940,075 Schuster Nov. 16, 1909 1,300,192 Overstrom Apr. 8, 1919 1,739,761 Kleinfeldt Dec. 17, 1929 1,941,770 Welsford Jan. 2, 1934 2,069,568 Wieder Feb. 2, 1937 FOREIGN PATENTS 87,553 Germany July 14, 1896 966,519 France Mar. 8, 1950 

